Once the data from the telescope has been collected it may need to be corrected for various known problems and then generally the data will be used to make some deductions about the parameters of the source being looked at. It is outside the scope of this section to attempt to describe all the possible ways of dealing with telescope data. However, some standard manipulations of data are nearly always necessary and a few other methods can be used to provide some first order checks for the results produced by the modelling programs described later in this thesis and these will be described here.